/* inih -- simple .INI file parser

SPDX-License-Identifier: BSD-3-Clause

Copyright (C) 2009-2020, Ben Hoyt

inih is released under the New BSD license (see LICENSE.txt). Go to the project
home page for more info:

https://github.com/benhoyt/inih

*/
int zsbl_isspace(int c);
#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS
#endif

#include <stdio.h>
#include <ctype.h>
#include <string.h>

#include "ini.h"

#if !INI_USE_STACK
#if INI_CUSTOM_ALLOCATOR
#include <stddef.h>
void* ini_malloc(size_t size);
void ini_free(void* ptr);
void* ini_realloc(void* ptr, size_t size);
#else
#include <stdlib.h>
#define ini_malloc malloc
#define ini_free free
#define ini_realloc realloc
#endif
#endif

#define MAX_SECTION 50
#define MAX_NAME 50

/* Used by ini_parse_string() to keep track of string parsing state. */
typedef struct {
	const char* ptr;
	size_t num_left;
} ini_parse_string_ctx;

/* Strip whitespace chars off end of given string, in place. Return s. */
static char* rstrip(char* s)
{
	char* p = s + strlen(s);
	while (p > s && zsbl_isspace((unsigned char)(*--p)))
		*p = '\0';
	return s;
}

/* Return pointer to first non-whitespace char in given string. */
static char* lskip(const char* s)
{
	while (*s && zsbl_isspace((unsigned char)(*s)))
		s++;
	return (char*)s;
}

/* Return pointer to first char (of chars) or inline comment in given string,
   or pointer to NUL at end of string if neither found. Inline comment must
   be prefixed by a whitespace character to register as a comment. */
static char* find_chars_or_comment(const char* s, const char* chars)
{
#if INI_ALLOW_INLINE_COMMENTS
	int was_space = 0;
	while (*s && (!chars || !strchr(chars, *s)) &&
			!(was_space && strchr(INI_INLINE_COMMENT_PREFIXES, *s))) {
		was_space = zsbl_isspace((unsigned char)(*s));
		s++;
	}
#else
	while (*s && (!chars || !strchr(chars, *s))) {
		s++;
	}
#endif
	return (char*)s;
}

/* Similar to strncpy, but ensures dest (size bytes) is
   NUL-terminated, and doesn't pad with NULs. */
static char* strncpy0(char* dest, const char* src, size_t size)
{
	/* Could use strncpy internally, but it causes gcc warnings (see issue #91) */
	size_t i;
	for (i = 0; i < size - 1 && src[i]; i++)
		dest[i] = src[i];
	dest[i] = '\0';
	return dest;
}

/* See documentation in header file. */
int ini_parse_stream(ini_reader reader, void* stream, ini_handler handler,
				     void* user)
{
	/* Uses a fair bit of stack (use heap instead if you need to) */
#if INI_USE_STACK
	char line[INI_MAX_LINE];
	size_t max_line = INI_MAX_LINE;
#else
	char* line;
	size_t max_line = INI_INITIAL_ALLOC;
#endif
#if INI_ALLOW_REALLOC && !INI_USE_STACK
	char* new_line;
	size_t offset;
#endif
	char section[MAX_SECTION] = "";
	char prev_name[MAX_NAME] = "";

	char* start;
	char* end;
	char* name;
	char* value;
	int lineno = 0;
	int error = 0;

#if !INI_USE_STACK
	line = (char*)ini_malloc(INI_INITIAL_ALLOC);
	if (!line) {
		return -2;
	}
#endif

#if INI_HANDLER_LINENO
#define HANDLER(u, s, n, v) handler(u, s, n, v, lineno)
#else
#define HANDLER(u, s, n, v) handler(u, s, n, v)
#endif

	/* Scan through stream line by line */
	while (reader(line, (int)max_line, stream) != NULL) {
#if INI_ALLOW_REALLOC && !INI_USE_STACK
		offset = strlen(line);
		while (offset == max_line - 1 && line[offset - 1] != '\n') {
			max_line *= 2;
			if (max_line > INI_MAX_LINE)
				max_line = INI_MAX_LINE;
			new_line = ini_realloc(line, max_line);
			if (!new_line) {
				ini_free(line);
				return -2;
			}
			line = new_line;
			if (reader(line + offset, (int)(max_line - offset), stream) == NULL)
				break;
			if (max_line >= INI_MAX_LINE)
				break;
			offset += strlen(line + offset);
		}
#endif

		lineno++;

		start = line;
#if INI_ALLOW_BOM
		if (lineno == 1 && (unsigned char)start[0] == 0xEF &&
						   (unsigned char)start[1] == 0xBB &&
						   (unsigned char)start[2] == 0xBF) {
			start += 3;
		}
#endif
		start = lskip(rstrip(start));

		if (strchr(INI_START_COMMENT_PREFIXES, *start)) {
			/* Start-of-line comment */
		}
#if INI_ALLOW_MULTILINE
		else if (*prev_name && *start && start > line) {
#if INI_ALLOW_INLINE_COMMENTS
			end = find_chars_or_comment(start, NULL);
			if (*end)
				*end = '\0';
			rstrip(start);
#endif
			/* Non-blank line with leading whitespace, treat as continuation
			   of previous name's value (as per Python configparser). */
			if (!HANDLER(user, section, prev_name, start) && !error)
				error = lineno;
		}
#endif
		else if (*start == '[') {
			/* A "[section]" line */
			end = find_chars_or_comment(start + 1, "]");
			if (*end == ']') {
				*end = '\0';
				strncpy0(section, start + 1, sizeof(section));
				*prev_name = '\0';
#if INI_CALL_HANDLER_ON_NEW_SECTION
				if (!HANDLER(user, section, NULL, NULL) && !error)
					error = lineno;
#endif
			}
			else if (!error) {
				/* No ']' found on section line */
				error = lineno;
			}
		}
		else if (*start) {
			/* Not a comment, must be a name[=:]value pair */
			end = find_chars_or_comment(start, "=:");
			if (*end == '=' || *end == ':') {
				*end = '\0';
				name = rstrip(start);
				value = end + 1;
#if INI_ALLOW_INLINE_COMMENTS
				end = find_chars_or_comment(value, NULL);
				if (*end)
					*end = '\0';
#endif
				value = lskip(value);
				rstrip(value);

				/* Valid name[=:]value pair found, call handler */
				strncpy0(prev_name, name, sizeof(prev_name));
				if (!HANDLER(user, section, name, value) && !error)
					error = lineno;
			}
			else if (!error) {
				/* No '=' or ':' found on name[=:]value line */
#if INI_ALLOW_NO_VALUE
				*end = '\0';
				name = rstrip(start);
				if (!HANDLER(user, section, name, NULL) && !error)
					error = lineno;
#else
				error = lineno;
#endif
			}
		}

#if INI_STOP_ON_FIRST_ERROR
		if (error)
			break;
#endif
	}

#if !INI_USE_STACK
	ini_free(line);
#endif

	return error;
}

/* See documentation in header file. */
int ini_parse_file(FILE* file, ini_handler handler, void* user)
{
	return ini_parse_stream((ini_reader)fgets, file, handler, user);
}

/* See documentation in header file. */
int ini_parse(const char* filename, ini_handler handler, void* user)
{
	FILE* file;
	int error;

	file = fopen(filename, "r");
	if (!file)
		return -1;
	error = ini_parse_file(file, handler, user);
	fclose(file);
	return error;
}

/* An ini_reader function to read the next line from a string buffer. This
   is the fgets() equivalent used by ini_parse_string(). */
static char* ini_reader_string(char* str, int num, void* stream) {
	ini_parse_string_ctx* ctx = (ini_parse_string_ctx*)stream;
	const char* ctx_ptr = ctx->ptr;
	size_t ctx_num_left = ctx->num_left;
	char* strp = str;
	char c;

	if (ctx_num_left == 0 || num < 2)
		return NULL;

	while (num > 1 && ctx_num_left != 0) {
		c = *ctx_ptr++;
		ctx_num_left--;
		*strp++ = c;
		if (c == '\n')
			break;
		num--;
	}

	*strp = '\0';
	ctx->ptr = ctx_ptr;
	ctx->num_left = ctx_num_left;
	return str;
}

/* See documentation in header file. */
int ini_parse_string(const char* string, ini_handler handler, void* user) {
	ini_parse_string_ctx ctx;

	ctx.ptr = string;
	ctx.num_left = strlen(string);
	return ini_parse_stream((ini_reader)ini_reader_string, &ctx, handler,
						    user);
}
